When conducting studies on how people react to different displays of emotion, actual human faces may not express those emotions exactly the same way each time, while photos or videos just aren't as impactful. That's why scientists have developed an expressive robotic head to do the job.
Known as Nikola, the "android child" head was created by a team from Japan's RIKEN Guardian Robot Project. It is capable of consistently displaying six emotions – happiness, sadness, fear, anger, surprise and disgust.
Along with its lifelike flexible silicone skin, Nikola incorporates 29 pneumatic actuators that control the movements of artificial muscles within its face. It utilizes an additional six actuators to move its head and eyeballs.
The locations of the actuators were determined using the existing Facial Action Coding System (FACS), which stipulates which biological "facial action units" – muscles or muscle groups, in other words – are used in the expression of specific emotions. Importantly, because the actuators are air-powered, they operate very smoothly and quietly. This makes Nikola seem more like a real child, and less like a robot.
In lab tests, volunteers were able to accurately identify which emotions Nikola was displaying, although some were easier to discern than others. For example, because the robot's skin doesn't wrinkle as readily as real human skin, its expression of disgust – in which the skin around the nose wrinkles – was harder to identify. The scientists are addressing such shortcomings as they develop the device further.
"In the short term, androids like Nikola can be important research tools for social psychology or even social neuroscience," said the lead scientist, Dr. Wataru Sato. "Compared with human confederates, androids are good at controlling behaviors and can facilitate rigorous empirical investigation of human social interactions."
Down the road, the technology might also be incorporated into full-bodied caregiving robots, which clients could relate to thanks to their expressive faces.
The research is described in a paper that was recently published in the journal Frontiers in Psychology.
Source: RIKEN